Tuesday, July 3, 2012

PARIS: A lab test to screen embryos for inherited risk of breast or ovarian cancer is "feasible" but controversy surrounding this method is unlikely to be stilled, a fertility conference heard on Monday. European researchers carried out the biggest-ever probe of a procedure to vet invitro embryos for gene mutations linked to these notorious cancers. Their work, presented at a conference in Istanbul, declared the test is a reliable indicator of whether the embryo carries the dangerous BRCA1 and BRCA2 gene variants . Even so, these genes are by no means a guarantee that cancer will occur, which means a fierce debate over the technique will continue, the researchers said.

The method, called preimplantation genetic diagnosis (PGD), entails taking cells from an IVF embryo while it is still in its earliest stage. If the embryo does not carry the flawed genes, it is deemed ready for transfer to the uterus , the next step of in-vitro fertilization (IVF). PGD has risen to prominence through screening for single-gene diseases such as cystic fibrosis that can doom a child to a life of sickness. Its use is now being widened to cover the inherited risk for cancer, but this is still at a fledgling stage as doctors debate the pros and cons. Presented at the annual conference of the European Society of Human Reproduction and Embryology, the new study looked at 717 IVF embryos that were screened for the BRCA1 and BRCA2 variants. Seventy couples who took part in the study had sought PGD because one partner had a family history of breast or ovarian cancer and they were afraid of handing the risk to their child.